An Alzheimer's disease which is one of dementia is the current major problem, and has been studied in the world without exception. One of main causes of the Alzheimer's disease is known as a protein called amyloid β accumulated in the brain. However, a diameter of the amyloid β is about 0.1 mm or less, and it is considered that the amyloid β cannot directly be portrayed by means of a current image detecting device for health care services.
By the way, most of medical imaging equipment such as an MRI is aimed at directly portraying a target tissue or lesions. However, in the medical field, there is a limitation of an imaging time, and there is a limitation of the resolution in the image which can be imaged within the limited time. Under the limitation, the target tissue or the lesions cannot be directly portrayed. Of course, in high-resolution image equipment, the portraying is possible, but the high-resolution image equipment is beyond a range of the health care services, and expensive.
Of course, in the case of using a superhigh magnetic MRI (for example, MRI of 7 Tesla and the like), direct portraying is possible, but the superhigh magnetic MRI is beyond the range of the health care services provided under medical insurance. An image diagnosis method requiring expensive equipment which is beyond the range of the health care services provided under medical insurance cannot be said as the solution of a current urgent medical problem, and a method of detecting a tissue or lesions, which cannot be portrayed by means of medical imaging equipment such as an MRI, realistically within a current range of health care services provided under medical insurance has been required.
For this reason, for example, the MR system disclosed in Patent Document 1 images a high-resolution MR image with a magnetic field strength of 3 tesla or more by using a 3D inclined double echo pulse sequence, and collects image data of the MR image for two different echo times so that a 3D phase image is collected.
In addition, in order to measure a predetermined component and a linear component regarding nonuniformity of the magnetic field, since a smoothing spherical harmonic function is subtracted from the measured value collected between the MRIs to obtain a local change of the magnetic field in the area of interest. Since ability to measure a magnetic field variation in the brain by the MRI is increased according to the square of B0, measurement of magnetism and iron of the brain is more sensitive according to the technique disclosed in the Patent Document 1.